Mounting for contact-fingers and method of adjusting the same



C. S. SNAVELY.

MOUNTING FOR CONTACT FINGERS AND METHOD OF ADJUSTING THE SAME. APPLICATION FILED 0Ec.15,191s.

l ,309, 1 O8. Patented July 8, 1919.

WITNESSES INVENTOR UNITED STATES PATENT OFFICE.

CLARENCE S. SNAVELY, OF-WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

MOUNTING- FOR CONTACT-FINGERS AND METHOD OF ADJUSTING THE SAME.

Specification of Letters Patent.

Patented July 8, 1919.

Application filed December 15, 1916. Serial No. 137,263.

ing therefor, by means of which the finger may be adjusted for proper contact operation, and maintained in such adjustment, without exposing the finger to any distortion or strain.

Another object of the invention is the rovision of a simple and efficient metho of using and treatingthe mounting to obtain and maintain the desired adjustment of the contact finger.

Other objects of the invention will appear I from a consideration of the following detailed description, taken in connection with the accompanying drawings forming a part of this specification, with the understanding, however, that the embodiments illustrated, though practical, are by no means the only embodiments which the invention may as sume, wherefore the invention is not confined to any strict conformity with the showing of the drawings, but may be changed and modified in various particulars within the scope of the appended claims.

In the drawings, Figure 1 is a view showing in side elevation a portion of a relay including one form of contact finger and mounting therefor embodying my invention. Fig. 2 is a transverse sectional view of the finger and mounting shown in Fig. 1 taken on the line IIII thereof.

Fig. 3 is a view showing in side elevation a modified form of the finger and mounting shown in Figs. 1 and 2.

Fig. 4 is a view showing in side elevatlon another form of mounting embodying my invention.

Fig; 5 is a view showing in side elevation one form of apparatus embodying mfy invention for ad usting the contact nger upon a carrier, the carrier, in this instance, being the one shown in Flg. 1.

Fig. 6 is a top plan view of the apparatus shown in Fig. 5.

Fig. 7 is a view showing in front elevation a modified form of the apparatus shown in Figs. 5' and 6, together with a modified form of mounting for the contact finger.

Fig. 8 is a View, showing in side elevation, the apparatus and mounting shown in Fig. 7.

Similar reference characters refer to similar parts throughout the several views.

Referring to the drawings in detail, and particularly to Figs. 1 and 2, M designates an electromagnet which is in this instance employed .to actuate a contact finger F. The electromagnet M is arranged vertically upon a support S and is provided with a pole-piece C located on the underside of such support, as shown. The pole-piece C is provided with a bracket B to which is pivoted an armature A. Rigidly secured to the underside of the armature A by means of the fastening members 10 is a carrier N for the contact finger F. This carrier is formed of rigid insulating material such as glass or bakelite, and, in this instance, its medial portion is secured to the armature A while the opposite ends thereof are inclined downwardly as at 11 and tapered from their free ends to the medial portion, as shown. The free ends of the carrier are formed upon their undersides with longitudinally extending grooves, or pockets P, P, to receive a bar'12. This bar 12 constitutes a part of the contact finger F, and as shown in this instance, is T-shaped in cross section, the

vertical portion thereof being disposed within the pockets P and retained therein by means of plastic substance X, such as cement or the like. One end of bar 12 is provided with a resilient tip 13. which is arranged at an upwardly extending angle for engagement with a stationary contact point or block 14. The block 14 is preferably formed of carbon, and is suitably secured to the underside of the support S in such manner as to dispose the contacting surface thereof in horizontal alineinent with the armature A when the latter is attracted by the electro-magnet M.

I am well aware of the fact that it has hitherto been proposed to construct a contact finger of a bar and resilient tip, and

to secure the same to and to actuate the same by an armature of, an electromagnet; and that the fingers are adjusted to engage properly with the stationary contacts, when the armature is attracted by the magnet, by manually bendin the tip. By means of my invention I eliminate this bending operation and accomplish the same result by adusting bar 12 with relation to the carrier h, thus allowing the bar and tip 13 to retain their natural positions and thereby eliminating strain or distortion thereof. I obtain this adjustment by first moving the armature A to its closed position, then while the plastic substance X is in a soft condition, I adjust the bar 12 within the pockets P, P until the tip 13 engages the block II in the desired manner and with the desired pressure. While the bar is in this adjusted position, the plastic substance is hardened, thus rigidly securing the bar in such position and providing a permanent adjustment for the tip to effectively engage the fixed contact when the armature is attracted.

In Fig. 3, I have shown a modified form of my invention in which the opposite ends of a carrier N are provided with openings to receive bolts or the like 15, by means of which a contact finger F is secured thereto, the contact finger, in this instance, comprising a flat bar 12 and a resilient tip 13. The bar 12 is formed with openings to receive the bolts 15, the bar being retained upon the mounting by means of the nuts 16. Surrounding the bolt openings and disposed upon the underside of the mounting N are pockets P, P, which are adapted to receive the plastic substance X. In this embodiment of my invention, the bar 12' is adjusted upon the bolts 15 in a manner similar to that described in my first form, by first placing a quantity of the plastic substance X within'the pockets P P, adjusting the bar and subsequently hardening the plastic substance to form a rigid seat upon which the barmay be clamped by means of the nuts 16, as will be understood. It will thus be seen that I have provided another means for permanently adjusting the bar without distorting or straining the same and that such adjustment is obtained irrespective of the tip 13, to cause the proper contacting of the tip with the block 14 .when the armature A is in attracted position.

In Fig. 4 a further modification is shown embodying the use of elastic members for maintaining an adjustment of the bar 12' upon the armature A without subjecting the bar to any injurious distortion or strain. In this instance, I mount the bar upon bolts 17 embedded in studs 18 of insulating material. The outer ends of the bolts are threaded to receive nuts 19 and washers 20, while surroundin the bolts and interposed between the was ers and bar are coiled expansible springs 21. constant pressure upon the bar 12 to support the bar in fixed position upon its mounting, such pressure, however, being just suflicient to prevent movement of the bar upon the bolts but not sufiicient to injuriously distort the bar. It will thus be seen that the bar althoughmounted in fixed position, is not rendered useless by its mounting but may be again used upon other mountings.

Referring to Figs. 5 and 6, a mechanical means is shown for automatically adjusting the bar 12 with relation to its carrier in such position that the tip 13 receives the same amount of compression as is exerted thereon by the armature when the latter is in closed position and the tip is in engagement with the contact 14. I have shown the apparatus applied to the form shown in Fig. l, the latter being inverted for obvious reasons. It is to be understood, however, that the apparatus may be used equally well with the form shown in Fig. 3. The apparatus com- These springs 21 maintain a r prises in this instance, a bracket 25 which is clamped to the pole-piece C by means of an integrally formed yoke Y. The yoke, as here shown, is of split annular formation, and is constricted by means of a screw 26 to engage and securely hold the same upon and in flush relation to the lower end of the polepiece C. Pivotedly connected to the bracket 25 is one end of an arm 27, the free end of which is enlarged and offset to constitute a weight 28 which normally forces the arm downwardly, as will be understood. The weight 28 is provided with a screw clamp 29 by means of which the bar 12 is rigidly connected to the arm, the jaws of the clamp being recessed to accommodate the fastening means for the tip 13.

In operation, it is assumed that the plastic substance X is in a pliable condition, whereupon the adjusting apparatus is applied, as shown, the weighted arm 27 moving the bar 12 downwardly to cause the tip 13 to engage the contact 14 with a pressure corresponding to the pressure exerted by the armature when the electromagnet is energized, thus insurmg a good contact between the tip and contact. This causes the bar 12 to embed itself in the plastic substance X and so to automatically adjust itself upon the carrier N in definite relation to the armature A. The ad ustment having been made, the substance X is then hardened, whe reby a permanent adjustment of the contact finger is obtained.

The apparatus may now be removed by;

means of the clamp and yoke, as will be; understood; thus it is obvious that the adjustment of the contact finger is maintained independently of the apparatus.

Fig. 7 is a modified formbf the apparatus shown in Figs. 5 and 6,,tliis embodiment being designed to. adjust the contact finger upon its mounting before the same is applied to the relay. This embodiment comprises a vertically disposed rod R mounted for vertical movement only in guide members G, G. The lower end of the rod is pro.- vided with an integrally formed yoke Z including spaced ears 30. The ears 30 are formed with openings to receive the opposite ends of a pintle 17, while pivotally mounted on the pintle and disposed between the ears 30 is a block 31. A plate 32 is detachably secured to the underside of the block 31 by means of screws 33 to form a clamp for receiving the bar 12' of the contact finger. As here shown, the bar 12 intersects the block at right angles to the direction of movement of the block to permit lateral movement of the bar when adjusting the same, as will be hereinafter described. The upper end of the rod R is provided with a flat head 3st upon which a weight 35 may be placed for moving the rod downwardly within the guide members G, G.

In this embodiment of my invention I have shown a slightly different means from that of Fig. 1 for mounting the contact finger F, such means comprising a substantially rectangular carrier N which has its outer side formed with recesses 36. The recesses 36 receive the plastic substance X for retainingthe bar 12' upon the mounting, while the bar, in this instance, is formed with angularly disposed pegs 37 adapted to'be embedded within the plastic substance, as shown.

When adjusting the contact finger, the carrier N" and armature A are arranged upon a suitable support (not shown) which also carries a stationary contact 14:, the relative positions of the armature and the stationary contact being the same as the relative positions of these members in a properly adjusted relay when the armature is attracted.

In operation, one end of the bar 12' is clamped tothe block 31, as shown, while its opposite end is placed upon the carrier N- in such manner as to embed the pegs 33 within the plastic material X, it being understood that the plastic material is now in a pliable condition.

The weight W is now placed upon the head 34, the weight being such as to exert a pressure upon the tip 13, through the medium of the rod R and the bar 12'. corresponding to the pressure applied to the tip when the armature of the relay is in attraced position. Thus the tip is now forced with this pressure into engagement with the fixed contact 14. During this operation, however, the bar 12 is caused to assume the proper relative position with respect to the armature A, the pivotal connection between the rod R and the bar, as well as the vertical movement of the rod permitting lateral as well as longitudinal movement of the bar to allow the same to assume whatever position it will under the action of the weight W.

It will thus be seen that the bar is adjusted with relation to its mounting and with relation to the contact l-l' so as to cause th tip 13 to properly engage the contact when in applied position upon a relay. While in this adjusted position the plastic material X is hardened to retain the pegs 33 therein, whereby a permanent adjustment of the contact finger is obtained. The finger and mounting may now be removed for application to a relay.

Having thus described my invention, what I claim is:

1. A method of adjusting a movable contact finger with relation to a stationary contact consisting in floating the finger in a plastic material, adjusting the finger to engage properly with the stationary contact, and then hardening the plastic material whereby a permanent adjustment of the finger is obtained.

2. A method of adjusting a contact finger upon an armature to obtain the desired com pression between the finger and a stationary contact when the finger isin closed position which consists of interposing between the finger and armature a plastic substance, mechanically exerting pressure upon the contact finger, and then hardening the plastic substance whereby the adjustment between the finger and armature is maintained.

3. In a relay, an electro-responsive device, a contact finger controlled thereby, said finger including a. resilient tip, a stationary contact, and means for permanently adjusting said finger independently of said tip to cause proper engagement of the tip with said stationary contact.

4. In a relay, an electro-responsive device, including an armature, a support carried by the armature, securing members mounted in the support, a contact finger removably mounted on the securing members, a stationary-contact engageable by said contact finger, and plastic material interposed between the contact finger and support for permitting adjustment of the contact finger with relation to the stationary contact.

5. The method of securing a relay contact finger to the armature, which consists in ad justably attaching the finger to the armature, exerting a pressure on said finger substantially equal to the pressure which will be exerted thereon by the relay winding. the finger being in engagement with a fixed member which occupies the same position with respect to the armature as the fixed contact member will occupy in the relay, and then rigidly attaching the finger to the armature in the position which it assumes un der such pressure.

6. A method of adjusting a contact finger upon an armature for proper engagement thereof with a fixed contact and at av pressure corresponding to the pressure exerted by the armature upon the finger when in active po- In testimony whereof I afiix my signature sition, which consists of interposing bein presence of two Witnesses.

tween the fin er and armature a lastic may Y T 7 terial, exerti g a predetermined gressure 0n CLARE) CE Sb AVELX the contact finger, and then hardening the Witnesses:

plastic material to obtain a permanent 2161-. A. HERMAN VVEGNER,

justment of the finger. EDWIN D. JONES.

Copies of this patent may be obtained for five cent: each, by addressing? the Gommissioner of Eaten, Washington, D. C. 

